Since a carbon fiber has extremely high specific strength and specific elastic modulus, a high thermal resistance and excellent chemical resisting performance, it is used as a reinforcing material for aerospace equipment as well as sports equipment and equipment for leisure time amusement, such as a golf club, a tennis racket and a fishing rod. When such a carbon fiber is used as a reinforcing material for these products, a carbon fiber bundle impregnated with an uncured resin composition, such as epoxy resin and unsaturated polyester is obtained first, and a plurality of such carbon fiber bundles are then arranged in one direction so that no clearances occur therebetween, to form a thin sheet type prepreg.
In recent years, it has been demanded that the weights of the above-mentioned products be reduced, and the reduction of the thickness of a sheet type prepreg has been in keen demand accordingly. In order to reduce the thickness of the prepreg, a carbon fiber bundle, which is a raw material of the prepreg, and which was formerly used in the shape of a rope, has come to be used in the shape of a non-twisted tape. This tape type non-twisted carbon fiber bundle is impregnated with a resin and then taken up once around a bobbin to be formed into a package. A sheet type prepreg is formed by withdrawing tape type carbon fiber bundles from a plurality of packages thus obtained and arranging these fiber bundles so that no clearances are left therebetween. In order to arrange the tape type carbon fiber bundles so as not to cause any clearance to occur therebetween as mentioned above, it is necessary that the width of each carbon fiber bundle be constant in the lengthwise direction thereof.
However, when a tape type non-twisted carbon fiber bundle is taken up around a bobbin in a conventional take-up apparatus as the fiber bundle is traversed on the bobbin, to be formed into a package, folds occur at the fold-back ends of the fiber bundle, so that the width of the fiber bundle cannot be set constant in the lengthwise direction thereof. A conventonal take-up apparatus consists of a feed roller 101, a pair of traverse guide rollers 102 and a bobbin 103 as shown schematically in FIG. 6. The traverse guide rollers 102 are disposed so that the axes thereof extend at right angles to that of the bobbin 103, and a tape type carbon fiber bundle F is supplied between these two guide rollers 102 so as to be held therebetween. The fiber bundle thus held between the guide rollers is taken up around the bobbin 103 to be formed into a package P as the fiber bundle F is traversed on the bobbin 103 reciprocatingly from one end thereof to the other in parallel with the axis thereof. While the tape type carbon fiber bundle F is taken up from the two guide rollers 102 around the bobbin 103, the flat surface of the fiber bundle F is twisted at 90.degree., and, moreover, the direction of the twist is reversed when the fiber bundle F is folded back at the end of each traversing. Therefore, for example, the tape type carbon fiber bundle F forms a fold f, in such a way that the bundle is bent over on itself with the upper surface turned facedown, on an end portion of the package P as shown in FIG. 7.
A tape type carbon fiber bundle F on which folds f occur as mentioned above is not smoothly unfolded when it is withdrawn from the package P to be formed into a sheet type prepreg, and clearances occur during such time among the parallel-fed fiber bundles. This causes the quality of a product made of a prepreg thus prepared to lower.